Processing facilities are typically managed using process control systems. Among other functions, these control systems often manage the use of valves, which control the flow of materials in the processing facilities. Example processing facilities include manufacturing plants, chemical plants, crude oil refineries, and ore processing plants. In these facilities, the valves may control the flow of water, oil, hydrochloric acid, or any other or additional materials in the facilities.
Linear variable differential transformers (LVDTs) are electro-mechanical transducers widely used to measure position or displacement. An LVDT may be used in a process control system to provide feedback relating to a physical position of a valve or other control device. In this example, a position of a magnetic core in the LVDT is sensed by the process control system. In some failure modes, a core may physically fall out of an LVDT. If this failure mode is not detected, the process control system may provide incorrect control signals to the associated control device. This may result in damage to the processing facility or dangerous conditions for personnel in the processing facility.